This invention relates to applicators for liquid or like fluent material, and in particular to hand-held applicators and dispensers for containing and applying fluent cosmetic material. The term "cosmetic material" is used herein broadly to designate material which is applicable to a portion of a user's face and/or other skin area and, in this broad sense, includes materials generally which alter, conceal or enhance appearance or odor or provide skin protection or treatment as thus applied.
In one specific aspect, the invention is directed to applicators and dispensers for liquid cosmetic material. The term "liquid cosmetic material" herein refers to cosmetic material which is in a liquid, semiliquid or pasty form, in contrast to more or less hard, solid shape-sustaining materials such as a conventional lipstick "bullet." Examples of liquid cosmetic material include liquid lip products (lip glosses, lip balms, lip moisturizers, lip coloring and long-lasting lipstick products), eye shadows and eye treatment systems. For purposes of specific illustration, detailed reference will be made herein to applicators for liquid cosmetic materials for the lips.
Present-day commercially available cosmetic materials for application to the lips are either in the form of a hard or semi-hard mass, such as lipstick bullets in various lengths and diameters, or are liquid cosmetic materials as defined above, having a viscosity that ranges from liquid to semiliquid or pasty. A typical viscosity range for liquid lip cosmetic materials is between about 1,500 and about 25,000 centipoise.
Today's lip and eye products are provided with many different types of applicators. The most popular and currently most widely used application systems for lipsticks are direct transfer types, wherein (in the case of hard or semi-hard products) the product is transferred from a lipstick bullet directly to the lips. In some instances the bullet is surrounded by a metal sleeve having an obliquely angled opening corresponding to the obliquely angled application surface of the bullet. Application of liquid lip (and eye) products is accomplished by either a pump system, where the product is pushed through the center of an application brush, or a container and rod system, the latter being very similar to mascara applicators with the exception that a knotted or gathered brush or a flocked tip is used to transfer the product from the container to the lips or eyes rather than a twisted wire brush as is commonly employed for mascara. All these systems have inherent problems.
The current trend in the cosmetic industry to favor softer (more liquid) products limits the use of bullet type application systems. Bullet type application is not feasible with the softer types of products because the cosmetic material bullet itself, which actually transfers the mass to the lips or eyes, does not have the strength (if it is constituted of such softer cosmetic material masses) to support the pressures of application; hence the bullet breaks off during the application or completely deforms into an unusable mass.
The pump/brush systems and the container/rod systems are a potential answer to the needs of application for softer masses. Unfortunately, both systems have application inadequacies and/or cost constraints. Pump/brush systems require re-education of the consumer for application, are more complex to use, require a certain dexterity, and give a different look after application (as compared to bullet type applicators), which is not always preferred by the users; also, they are complex and costly mechanisms.
The container/rod systems have limitations in their ability to apply higher viscosity products (within the liquid cosmetic material viscosity range) because these systems require a certain degree of cold flow of product to enable the product to coat the applicator evenly, which in turn is necessary for proper and even application. With the higher viscosity liquids these applicators tend to clump the product unevenly rather than to apply a continuous dose. Also there is an inconvenience with these systems in that the applicator is at some distance from the holding point (the cap) and its satisfactory manipulation thus requires some dexterity and coordination during application, unlike the bullet type lipstick which the consumer can hold very close to the point of application thereby easily maintaining very precise control.
In a second aspect, the invention is directed to applicators and dispensers for microcapsules. It is known to provide fluent, e.g. liquid, cosmetic materials in microcapsules having a rupturable shell, e.g., to protect the contained material from exposure to air before application. The size of the microcapsules typically or generally ranges from about one to about 1200 microns in size. A preferred range, for at least many purposes, is between about 5 and about 500 microns. Materials used in making the capsule shell may include, without limitation, natural or organic materials such as gelatin, gum arabic, agar, sugar, starch and even metals; semisynthetic polymers such as cellulose acetate and hydroxpropylcellulose; and synthetic polymers such as acrylpolymers, PVA, polyester and nylon.
Currently most, if not all, cosmetic products (primarily treatment products) provided in the form of microcapsules are applied by hand. This is due to the fact that the microcapsules need to be broken to release the active ingredient encapsulated in them. The action of rubbing and pressure produced during the hand application process breaks the microcapsules. This process of application does not always guarantee the breakage of the microcapsules, however, because it is very dependent on the amount of rubbing and pressure exerted by the user during the application. Another problem with hand application is lack of precision or metering of the microencapsulated product.